Portable ladder



May 2, 1950 Filed May 3, 1946 E. BOGGS PORTABLE LADDER 2 Sheets-Sheet 1FIG. 2

INVENTOR ERNEST BOGGS ATTORNEY.

E. BOGGS PORTABLE LADDER May 2, .1950

2 Sheets-Sheet 2 Filed May 3, 1946 FIG.4

INVENTOR ERNEST BOGGS ww fl 9944 1 A TTORNEY Patented May 2, 1950 UNITEDSTATES PATENT OFF-ICE (Granted underthe act of March 3, 1883,45 amended-April-30, 1928; 370 0. G. 757) .1 la m The invention described hereinmay be manufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

The invention to be hereinafter described relates to portable ladders.

The main objects of the present invention are to overcome and eliminateor greatly minimize objections and disadvantages of wheel-mountedladders and especially to provide a simple, compact, efllcient, safe andreliable means applicable to the stepladder type of ladders making themreadily portable or transportable from one place to another andrendering them thoroughly safe against dangerous accidental skidding,slipping or like displacements.

An important aim of the invention is to present a portablecaster-mounted ladder of novel construction for grounding" the structureby elevating the casters, and which may be economically constructed bythe average carpenter from stock lumber and hinges.

In order to more clearly disclose the construction, operation and use ofthe invention reference should be had to the accompanying drawingsforming part of the present application.

In the drawings:

Fig. 1 is a side elevation, partly broken away, of a ladder with theinvention applied and in operative or travel position;

Fig. 2 is a like view with the invention in inoperative or groundedposition;

Fig. 3 is a bottom plan view of Fig. 1; and

Fig. 4 is a top plan view of Fig. l, the ladder being cut ofi at a pointdirectly above the base frame, the upper framework of the ladder itselfbeing omitted.

Fig. 5 is an enlarged detail of a. hinge between the toggle and ladderbase.

There is shown a ladder or stair I, which, with a conventional trussframe work, is supported on a horizontal rectangular base A, consistingprincipally of two parallel side stringers l5 and two cross beams 16 atthe under side set edgewise against the stringers. The latter constitutefoot pieces for the base, to rest upon the ground at times. To this baseare hinged two triangular frames 2, by ordinary plate hinges 3 at theirbases, as, for instance, in Fig. 5, or any other suitable meanspermitting the frames to be swung upwardly from such connections.Preferably, these frames are flexibly connected at their adjacent anglesin such manner that they may move from a flat, lowered or operativeposition to a flexed,

4 is very practical, and, in effect, makes a toggle lever unit of thetwo frames. Each of these frames carries on its underside, at the twocorners thereof nearest the hinges 3, swivelled castors 5. The parts areso proportioned and assembled that when the frames 2 are swung down intothe same plane, the supporting rollers of the castors 5 will be forcedappreciably below the plane of the ladder feet is thereby lifting theladder from its feet and transferring its weight to the castors on theframe A and making it portable. To spread the toggle and. transfer theladder weight to the eastors a hand lever 6 is provided. Lever 6 has oneend pivoted at I to the rear truss framework of the ladder. At about itscenter it is connected pivotally to a bar 8 which extends downward fromthe lever toward base A. The lower end of the bar 8 is hinged at 9 to across bar in over the base A which extends across the latter to the faror left side, where it is hinged or otherwise suitably connected at H tothe side member [5 of frame A. It will be noticed that bar It extendsacross the ladder a short distance above the hinge 4 at the center ofthe toggle formed by the frames 2. At that point a short presser blockor the like [2 is set between bar It and the inner angle of one memberof the toggle. By depressing lever B the ladder may be transferred fromits feet to the castors and made portable. By swinging the end of thelever 6 beneath the stop block 13 on the side of a newel I'I beside theladder, the eastors may be indefinitely kept this way. As soon as thelever is disengaged from block 13 and relieved of manual pressure, theweight of the ladder will, of course, force the frames 2 up so thatcastors 5, though in light engagement with the supporting surface, willbe ineffective as supports, as may be seen in Fig. 2.

By providing swivel mounting of the castors the ladder may be turnedabout, steered and guided in any direction desired toward, along orbetgreen stacks and storage piles without diilicul As will be readilyseen on reference to the drawings, the lever 6 is within easy reach ofanyone standing on the ground by the ladder.

Many changes may be made in the construction, arrangement anddisposition of the various parts of the'invention within the scope ofthe appended claims without departing from the invention, and it ismeant to include all such within this application wherein only onepreferred form has been illustrated, purely by way of example and withno thought or intention to, in

tipped or angular position. A simp Pla e hi g any degree, limit theinvention thereby.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

In a ladder truck, a base frame having ground engaging feet to supportthe same, two planiform lever frames having base edges extending thewidth of the base frame pivoted at opposite ends of the base frame andpivotally connected mutually to form a toggle unit, a cross leverpivoted on one side of the base frame, a presser member intermediatelyof the cross lever between the cross lever and at least one togglemember, a hand lever of the second order pivoted at the side of theframe adjacent the free end of the ERNEST BOGGS.

REFERENCES CITED The following references are of record in the a op 10file of this patent:

. UNITED STATES PATENTS Number Name Date 705,905 Centner July 29, 1902970,860 Terriif Sept. 20, 1910 506,441 Nunn Aug. 26, 1924 1,759,424Strauss May 20, 1930 2,309,214 Rey Jan. 26, 1943 2,371,092 Williams Mar.6, 1945

